Overcharging battery (CB400)

[Xile]

Ok,
it's two times now: while riding, i loose power until the bike won't start anymore, no lights or anything> flat battery!
Opening my seat: sulfure smell and condensation all over and boiling hot battery. Happened the first time on monday, after I dropped my bike onmy driveway on the morning. Went to Honda Warkworth: changed the battery, checked all the connections, sweet as.
TODAY, same thing, battery totally dead and hot, condensation etc.
My bike is a CB400 super sport from 1994, a battery is worse $110, and i'm not going to change it every week

Battery is a 12volts, but mine is charging 17volts when off, and 21 volts when running!!!

What could it be? and how could I fix it..?
Thanks for your help guys!

*desperate sight*
Cecile

[FROSTY:Me]

YOUR REGULATOR/RECTIFYER HAS GONE BYE BYES.yOU NEED A NEW ONE

A very temporrary solution is to find the plug from the charging system and unplug it . Ride the bike for half an hour then plug it back in for half an hour. -its just a get you home type solution.

[notme]

.....mine is charging 17volts when off, and 21 volts when running!!!....

Bugger me mate - those voltages are all kinds of wrong. DON'T put another battery in there, you will kill it. Are you saying that you took it to a bike shop and they sold you a battery and THEY measured those voltages? Surely not....if that was the case they owe you a free battery!

Most likely the regulator/rectifier is at fault, you should be able to get one cheapish from a wreckers or tardme and it will be a plug in fix job.

Unfortunatley you will need a third battery, but as noted above, if the actual bike was anywhere near a bike shop and they didn't spot that the battery was being boiled then they need an attitude adjustment, size 12 steelcap for preference.

[notme]

oh and check all your brake/headlight/indicator bulbs - you may have some blown ones....

[Xile]

if that was the case they owe you a free battery!

I'm counting on this ey!!!

[Xile]

Bugger me mate - those voltages are all kinds of wrong. DON'T put another battery in there, you will kill it. Are you saying that you took it to a bike shop and they sold you a battery and THEY measured those voltages? Surely not....if that was the case they owe you a free battery!

Most likely the regulator/rectifier is at fault, you should be able to get one cheapish from a wreckers or tardme and it will be a plug in fix job.

Unfortunatley you will need a third battery, but as noted above, if the actual bike was anywhere near a bike shop and they didn't spot that the battery was being boiled then they need an attitude adjustment, size 12 steelcap for preference.

YOUR REGULATOR/RECTIFYER HAS GONE BYE BYES.yOU NEED A NEW ONE

A very temporrary solution is to find the plug from the charging system and unplug it . Ride the bike for half an hour then plug it back in for half an hour. -its just a get you home type solution.

mm so rectifier.. i'm going to try to find one ey...
never see such a plug, frosty, but it THE occasion to find it!

[Henk]

The plug you are looking for will have 5 or 6 wires and three will be the same colour. It will come from the left or right crank end cover, probably the left

[mnkyboy]

Follow the wires from the rectifier that we pulled out cecile - it traces back to a plug.

BTW was good to meet you yesterday...

[notme]

Follow the wires from the rectifier that we pulled out cecile - it traces back to a plug...

So it's on the way to being replaced then? good stuff. The chart attached might be useful in future too...

[Xile]

Right,
Battery is working, and all the wires checked (Thanks for the map Allun).
A new rectifier is about $270.

So i'm looking for a rectifier/regulator 12V 35amp, one plug with 3 yellow wires, the other with 2 green and 2 white/red wires..ANyone please?

[notme]

Yellow pages - bike wreckers, call them and ask for a reg/rect for your model and year...... don't buy a new one!

You can get them for as cheap as $35 if the wrecker has a few of them....

[davereid]

The voltages you mentioned are very high.

I assume the 17 volts you observed with the motor OFF, was measured within a few seconds of the engine running ?

If you see 17 volts on a 12 volt battery that is not under charge, you likely have a faulty voltmeter, as this is not possible from a 12v battery.

It may pay to re-check those readings.

[davereid]

If you are sure it is the rectifier you can easily and cheaply make a new one. You need a pair of bridge rectifiers, like Dick Smith Z3336 @ $10 is fine.

Connect all the "+" terminals and all the "-" terminals together.

Connect the 3 phases of your stator to the "~" terminals. (You will have a spare "~" terminal, it doesnt matter.)

Job done, a universal 35 amp, 1-2-3-4 phase rectifier for $20.

[notme]

If you are sure it is the rectifier you can easily and cheaply make a new one. You need a pair of bridgge rectifiers, like Dick Smith Z3336 @ $10 is fine.

Connect all the "+" terminals and all the "-" terminals together.

Connect the 3 phases of your stator to the "~" terminals. (You will have a spare "~" terminal, it doesnt matter.)

Job done, a universal 35 amp, 1-2-3-4 phase rectifier for $20.

Close, but no cigar. the RR's on bikes aren't quite as simple as that unfortunately. Xile, the best fix for your situation is finding a reg/rect at a wreckers or trademe etc.

[Xile]

Found a spare one and a spare battery too: enough to go home safely..
I'm gonna go for the replacement of my battery by the warkworth guys, and look on trademe/wreckers to find a new RR...
Thanks for your help guys!!